Thermoplastic composition

ABSTRACT

The subject invention discloses thermoplastic composition which is comprised of a blend of a thermoplastic polyolefin resin and a modified elastomer, wherein said thermoplastic polyolefin resin selected at least from the group of polyethylene, isotactic polypropylene, syndiotactic polypropylene, polypropylene impact copolymers containing about 1-7% by weight of ethylene, butene, hexene, or octene, polyolefin copolymers such as ethylene-butene, hexene, or octene, polybutene, reactor grade modified polypropylene, metallocene polypropylene, oxypolypropylene, wherein said modified elastomer is comprised of a conjugated diene selected from 1,3-butadiene and isoprene, wherein said modified elastomer is highly branched, wherein said modified elastomer is characterized by having a G′ and G″ frequency crossover of no more than 4 radians/s at 100° C., wherein the thermoplastic polyolefin is present in an amount which is within the range of about 5 parts by weight to about 95 parts by weight, and wherein the modified elastomer is present in an amount which is within the range of about 5 parts by weight to about 95 parts by weight, based upon the total weight of the thermoplastic composition. The present invention also discloses a process for preparing a thermoplastic composition which comprised (1) mixing a thermoplastic polyolefin resin and a modified elastomer at a temperature about or above the melting point of the thermoplastic resin in a mixing devise, (2) discharging the mixed blend from the mixing devise, and (3) forming the mixed blend into a pellet, sheet, or article of manufacture, wherein said thermoplastic polyolefin resin selected at least from the group of polyethylene, isotactic polypropylene, syndiotactic polypropylene, polypropylene impact copolymers containing about 1-7% by weight of ethylene, butene, hexene, or octene, polyolefin copolymers such as ethylene-butene, hexene, or octene, polybutene, reactor grade modified polypropylene, metallocene polypropylene, oxypolyolefin, wherein said modified elastomer is comprised of a conjugated diene selected from 1,3-butadiene and isoprene, wherein said modified elastomer is highly branched, wherein said modified elastomer is characterized by having a G′ and G″ frequency crossover of no more than 4 radians/s at 100° C., wherein the thermoplastic polyolefin is present in an amount which is within the range of about 5 parts by weight to about 95 parts by weight, and wherein the modified elastomer is present in an amount which is within the range of about 5 parts by weight to about 95 parts by weight, based upon the total weight of the thermoplastic composition.

BACKGROUND OF THE INVENTION

[0001] U.S. Pat. No. 3,758,643 discloses blends of partially curedmonoolefin rubber such as EPDM or EPM with a polyolefin resin(polypropylene) where the rubber phase was cured with a peroxide. Thecompositions were useful as thermoplastic elastomers.

[0002] U.S. Pat. No. 4,104,210 discloses compositions of blends ofvulcanized high diene rubbers with crystalline thermoplastic polyolefinresins. The diene rubbers include copolymers of diene with styrene,vinyl pyridine, acrylonitrile or methacrylonitrile. The diene rubbercontent in the blends is about 75-55 parts by weight and thethermoplastic polyolefin content is 25-45 parts by weight and the dienewas highly crosslinked. U.S. Pat. No. 4,104,210 does not disclose thatuseful blend compositions can be obtained when the diene copolymerrubber comprises of multiple arms and is coupled with tin or silicon, italso does not disclose that thermoplastic blend compositions that haveimproved processability in injection molding and extrusion can bedeveloped with the tin or silicon-coupled diene copolymer rubbers andcopolymer rubbers that are highly branched. The subject patent also doesnot suggest that the diene-based rubbers used in the blends may compriseof copolymers of 1,3-diene polybutadiene and isoprene.

[0003] U.S. Pat. No. 4,130,535 discloses blends of polyolefin resins andcompletely cured monoolefin copolymer rubber such asEthylene-Propylene-Diene rubber.

[0004] U.S. Pat. No. 4,183,876 discloses thermoplastic compositions ofcrystalline thermoplastic polyolefin resins and cross-linkedpolyalkenamer rubber.

[0005] U.S. Pat. No. 4,202,801 discloses dynamically and partially curedblends of monoolefin copolymer rubbers such as ethylene-propylenecopolymer rubbers or ethylene-propylene-diene terpolymer rubbers,polyolefin resin, and conjugated diene rubbers such as cis-1,4polyisoprene or cis-polybutadiene or polychloroprene.

[0006] U.S. Pat. No. 4,203,884 discloses blends of polynorborene,plasticizer, and thermoplastic polyolefin resin.

[0007] U.S. Pat. No. 4,250,273 discloses thermoplastic ter-blendcompositions comprising of about 10 to 50 parts of a crystalline1-olefin polymer, about 80 to 15 parts of a random styrene-butadienerubber copolymer and from about 5 to 55 parts of a highly saturatedelastomer. The invention also related to ter-blends where the rubbersare partially vulcanized. U.S. Pat. No. 4,250,273 does not disclose thatuseful blend compositions can be obtained when the diene copolymerrubber comprises of multiple arms and is coupled with tin or silicon, italso does not disclose that high impact blend compositions can bedeveloped with the tin or silicon-coupled diene copolymer rubbersFurther, it does not suggest that a binary blend composition of astyrene-butadiene copolymer rubber and a thermoplastic olefin resin canbe used to make useful compositions with good surface appearance andphysical properties.

[0008] U.S. Pat. No. 4,311,628 relates to blends of polypropylene andEPDM where EPDM was cured with phenolic resins for better oilresistance.

[0009] U.S. Pat. No. 4,271,049 discloses blends of crystallinepolypropylene and cured rubbers including styrene-butadiene rubber up to25 weight % styrene or alpha-methyl styrene and the rubber is cured withphenolic or urethane or sulfur donor curative. The preferredcompositions were from 25-75 parts of polypropylene and about 75-25parts of rubber. Furthermore, U.S. Pat. No. 4,271,049 does not teachthat useful blend compositions can be obtained when SBR rubber comprisesof multiple arms and is coupled with tin or silicon, it also does notdisclose that high impact blend compositions can be developed with thetin or silicon-coupled diene copolymer rubbers.

[0010] U.S. Pat. No. 4,183,876 teaches blends of crosslinkedpolyalkenamer rubber and crystalline thermoplastic blends.

[0011] U.S. Pat. No. 4,340,684 is similar to U.S. Pat. No. 4,250,273 andfurther teaches partial curing of the rubber and narrows the claims forthe melt flow rate of the formed blend. The Styrene content in the SBRrubber is up to 40% by weight of the said rubber. U.S. Pat. No.4,340,684 does not disclose that useful blend compositions can beobtained when the diene copolymer rubber comprises of multiple arms andis coupled with tin or silicon, it also does not disclose that thatcompositions that have improved processability in injection molding andextrusion can be developed with the tin or silicon-coupled dienecopolymer rubbers. Further, it does not suggest that a binary blendcomposition of a styrene-butadiene copolymer rubber and a thermoplasticolefin resin can be used to make useful compositions with good surfaceappearance and physical properties.

[0012] U.S. Pat. No. 4,343,918 claims processes for making blendsprimarily disclosed in U.S. Pat. No. 4,250,273.

[0013] U.S. Pat. No. 4,594,390 discloses a process for preparation ofthermoplastic elastomers of polypropylene and EPDM under conditions ofhigh shear required for dynamic vulcanization of the EPDM.

[0014] U.S. Pat. No. 4,927,882 discloses thermoplastic elastomerproduced by dynamic vulcanization of SBR to form a dispersed phase ofcrosslinked SBR in a co-continuos phase of SEBS and polypropylene. Theblends were useful in pharmaceutical, consumer and health industries.

[0015] U.S. Pat. No. 5,021,500 teaches TPO compositions prepared with acrystalline thermoplastic resin and a halobutyl rubber.

[0016] U.S. Pat. No. 5,051,478 provides a dynamically vulcanizedcomposition comprising of a polyolefin resin, an elastomer, and anethylene copolymer resin such as a copolymer of ethylene and vinylacetate or an alkyl acrylate.

[0017] U.S. Pat. No. 5,248,729 suggests the process for makingthermoplastic composition by heat treating a mixture of a thermoplasticresin with no olefinic unsaturated carbon-carbon bond, an elastomer fromthe group of SBS, SIS, 1,2-polybutadiene rubber, and EPDM rubber, with acrosslinking agent of dihydroaromatic compound.

[0018] U.S. Pat. No. 5,523,356 teaches blends obtained by dynamicvulcanization of polypropylene, polyisobutene, EPDM rubber, andpolybutadiene.

[0019] U.S. Pat. No. 5,621,045 discloses thermoplastic vulcanizates fromsemi-crystalline polyolefins and blends of crosslinked rubbers with onerubber being C4 to C7 isomonoolefin based (isobutylene) and rubber beingEPDM or rubbers derived from a conjugated diene.

[0020] U.S. Pat. No. 6,051,681 discloses process for preparation ofthermoplastic elastomer with a rubber such as ethylene-alpha-olefindiene terpolymer (EPDM) and a thermoplastic resin, phenolic curative, ahydrotalcite and a HALS compound.

[0021] U.S. Pat. No. 6,207,761 discloses thermoplastic ionomer blend oralloy composition containing an ionomer, crosslinked rubber andpolyolefin resins.

SUMMARY OF THE INVENTION

[0022] The subject invention discloses thermoplastic composition whichis comprised of a blend of a thermoplastic polyolefin resin and amodified elastomer, wherein said thermoplastic polyolefin resin selectedat least from the group of polyethylene, isotactic polypropylene,syndiotactic polypropylene, polypropylene impact copolymers containingabout 1-7% by weight of ethylene, butene, hexene, or octene, polyolefincopolymers such as ethylene-butene, hexene, or octene, polybutene,reactor grade modified polypropylene, metallocene polypropylene,oxypolyolefin, wherein said modified elastomer is comprised of aconjugated diene selected from 1,3-butadiene and isoprene, wherein saidmodified elastomer is highly branched, wherein said modified elastomeris characterized by having a G′ and G″ frequency crossover of no morethan 4 radians/s at 100° C., wherein the thermoplastic polyolefin ispresent in an amount which is within the range of about 5 parts byweight to about 95 parts by weight, and wherein the modified elastomeris present in an amount which is within the range of about 5 parts byweight to about 95 parts by weight, based upon the total weight of thethermoplastic composition. Oxypolyolefins are polyolefins that typicallycontain less than 1% repeat units of the —O—(CH₂)_(n)— structure.

[0023] The present invention also discloses a process for preparing athermoplastic composition which comprised (1) mixing a thermoplasticpolyolefin resin and a modified elastomer at a temperature about orabove the melting point of the thermoplastic resin in a mixing devise,(2) discharging the mixed blend from the mixing devise, and (3) formingthe mixed blend into a pellet, sheet, or article of manufacture, whereinsaid thermoplastic polyolefin resin selected at least from the group ofpolyethylene, isotactic polypropylene, syndiotactic polypropylene,polypropylene impact copolymers containing about 1-7% by weight ofethylene, butene, hexene, or octene, polyolefin copolymers such asethylene-butene, hexene, or octene, polybutene, reactor grade modifiedpolypropylene, metallocene polypropylene, oxypolyolefin, wherein saidmodified elastomer is comprised of a conjugated diene selected from1,3-butadiene and isoprene, wherein said modified elastomer is highlybranched, wherein said modified elastomer is characterized by having aG′ and G″ frequency crossover of no more than 4 radians/s at 100° C.,wherein the thermoplastic polyolefin is present in an amount which iswithin the range of about 5 parts by weight to about 95 parts by weight,and wherein the modified elastomer is present in an amount which iswithin the range of about 5 parts by weight to about 95 parts by weight,based upon the total weight of the thermoplastic composition.

[0024] The thermoplastic compositions of this invention are particularlyuseful for manufacturing automotive interior panels, automotive exteriorbody panels, automotive instrument panels, soft-touch parts, householdappliances, household goods, toys, razor holders, razor handles, staplerhandles, pen grips, computer housings, and computer key boards.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a schematic view of an extruder that can be utilized incarrying out the subject invention.

[0026]FIG. 2 is a top plan view of a flower holder cap for a singleflower.

[0027]FIG. 3 is a side view of the flower holder cap for a singleflower.

[0028]FIG. 4 is a fragmentary view of a single flower transportationvial wherein the flowers in the flower arrangement are held in placewith a flower holder cap for a multiple flower arrangement.

[0029]FIG. 5 is a top perspective view of a flower holder cap for asingle flower equipped with a removal tab.

[0030]FIG. 6 is a top plan view of a flower holder cap for anarrangement of multiple flowers.

[0031]FIG. 7 is a side view of the flower holder cap for an arrangementof multiple flowers.

[0032]FIG. 8 is a top perspective view of a flower holder cap for anarrangement of multiple flowers equipped with a removal tab.

[0033]FIG. 9 is a fragmentary view of a flower arrangement in a vasewherein the flowers in the flower arrangement are held in place with aflower holder cap for a multiple flower arrangement.

DETAILED DESCRIPTION OF THE INVENTION

[0034] In accordance with this invention, elasto-plastic blends of adiene elastomer coupled with silicon or tin with thermoplastic olefinicresins are disclosed. Such thermoplastic blends have high impactstrength and good balance of physical properties. The elastomers havelow glass transition temperatures for providing low temperature impactproperties. Also disclosed is the preferred process of preparing suchblends. These blends may have several useful applications such asautomotive exterior, interior, body panels, household articles,appliance parts, toys etc. Further more, the crumb form of the dienerubber with tin or silica coupling or a higher degree of branching, hashigh resistance to cold flow and allows to be fed into continuous mixingequipment such as a twin-screw extruder without being appreciablyre-agglomerated.

[0035] Thermoplastic olefins (TPOs) are widely used in an automobile.The fascia or bumpers or side impact panels form a major portion of theTPO usage. More recently TPOs are also being used in automotive interiorapplications and are also being used for PVC replacement. These TPOs aregenerally comprised of blends of a thermoplastic olefin such aspolypropylene. Since the glass transition temperature of thepolypropylene ranges from about −10° C. to 10° C. and is not low enough,it possesses inferior low temperature impact properties. Therefore, theTPO additionally consists of an elastomeric phase that has a lower glasstransition temperature (T_(g)) for providing the necessary coldtemperature impact properties. The elastomers used are generallyolefinic based with either low diene unsaturation or no dieneunsaturation. The olefinic elastomers with low diene unsaturation areter-polymers of ethylene, propylene, and a non-conjugated diene basedmonomer (EPDM). The olefinic elastomers with no diene unsaturation maybe ethylene-propylene copolymers. More recently these no-dieneelastomers have been metallocene-based ethylene elastomers. Theelastomers may be incorporated in the thermoplastic olefinic resin suchas polypropylene in a compounding step and the resulting TPOs are calledCompounded-TPOs or C-TPOs. Some of the elastomers may be incorporated inthe polypropylene resin in the second reactor following thepolymerization of the polypropylene in the first reactor. Such TPOs aregenerally called Reactor-TPOs or R-TPOs.

[0036] The elastomeric phase in the TPOs is generally dispersed whenTPOs of higher stiffness are obtained without adding any reinforcementfillers. The elastomeric phase may be co-continuous with thethermoplastic resin phase if greater level of flexibility is required,without appreciably sacrificing the thermoplasticity. The elastomerphase may be non-crosslinked or partially crosslinked. For the sake ofthis invention, the TPOs are considered blends of a thermoplasticolefinic resin and an elastomer where the thermoplastic content is highenough and the elastomer may or may not be. There is considerable priorart mentioning the use of other compounding ingredients such as talc, UVstabilizers, antioxidants, processing aids, oils, colorants, adhesionpromoter's etc. that may also be a part of the TPO composition.

[0037] If in such thermoplastic blends the elastomer content is highenough and yet not too high as it is in the vulcanized and thermosettingrubber articles such as tires, the blends tend to render elastomer likeproperties without losing the thermoplasticity. In other words, when thethermoplastic blends or their articles, are stretched and released, theytend to somewhat return to their original state in a nominal time periodand are still re-processable as thermoplastics. Such blends may often becalled as thermoplastic elastomers or TPEs. If the elastomeric phase inthe TPEs is crosslinked or vulcanized, preferably highly crosslinked andmostly during the preparation of the said blends, the TPEs may alsocalled as Thermoplastic Vulcanizates or TPVs. High degree ofcrosslinking enables greater elasticity and low compression set andgenerally higher oil resistance compared to their uncrosslinked analogs.For the sake of this invention, above definitions of TPO, TPE and TPVwill be generally applicable to describe the compositions and processesper this invention. In this invention, elastomers and rubbers are usedinterchangeably. In this invention, vulcanized, crosslinked, and curedterms are also used interchangeably.

[0038] U.S. Pat. No. 3,758,643, U.S. Pat. No. 3,806,558, U.S. Pat. No.4,104,210, U.S. Pat. No. 4,130,535, U.S. Pat. No. 4,183,876, U.S. Pat.No. 4,202,801, U.S. Pat. No. 4,271,049, U.S. Pat. No. 4,340,684, U.S.Pat. No. 4,250,273, U.S. Pat. No. 4,343,918, U.S. Pat. No. 4,927,882,U.S. Pat. No. 4,311,628, U.S. Pat. No. 5,523,356, U.S. Pat. No.5,248,729, U.S. Pat. No. 5,021,500, U.S. Pat. No. 5,051,478, and U.S.Pat. No. 5,925,703 provide compositions, methods, examples of severalvarieties of TPOs, TPEs, and TPVs, and incorporated herein as areference.

[0039] The thermoplastic polyolefins that are generally used in theblends are polypropylene, polyethylene, and polybutenes. Generally atleast one type of polypropylene is employed. The polypropylene isgenerally isotactic form of homopolymer but other forms of polypropylenesuch as syndiotactic or atactic may also be used as a part of the blend.Polypropylene impact copolymers wherein in a second copolymerizationstep, ethylene is reacted with polypropylene, may also be employed.Polypropylene random copolymers that usually contain 1-7% ethylenecopolymerized with polypropylene can also be used. The reactor gradeimpact modified polypropylene can also be used. A publication article inModern Plastics Encyclopedia/89, mid October 1988 Issue Volume 65,Number 11, pages 86-92, describes several types of polypropylenes, whichis incorporated herein as a reference for the types of polypropylenesthat may be used in the blends of the said invention. Metallocene basedpolypropylene resins that may be generally produced by single-sitetechnology may also be used. The polypropylene produced by methods thatwere presented in following article may also be used, which isincorporated as a reference “Metocene TM, Precise Tailoring ofPolypropylene Resins Using Single-Site Technology, David Fischer,Presented at the SPE Automotive TPO Global Conference 2001, HyattRegency, Dearborn, Mich., Oct. 1-3, 2001.

[0040] The thermoplastic olefins may have a melt flow rate that isgenerally greater than 0.5 g/10 minutes as measured per ASTM 1238 at 230C/2.16 Kg load. Higher melt flow rate resins may be preferred for TPOapplications that require better flow. For TPO applications, it is morepreferred to use resins with melt flow rate that is greater than atleast 5 g/10 min, more preferably greater than 10 g/min., and mostpreferably greater than 20 g/10 minutes.

[0041] The diene elastomers that are generally prepared by solutionpolymerization techniques were described in Paper No 158, at the RubberDivision Meeting of the American Chemical Society, Orlando, Fla., Sep.21-24, 1999. The solution rubbers that are particularly more useful inthis invention are the modified elastomer such as copolymers of styreneand diene selected from butadiene and isoprene and the living polymer,before terminating the polymerization, modified with tin or silicon.Such modified elastomers may also be for example styrene/butadienecopolymers and styrene/isoprene/butadiene ter-polymers. Homopolymers ofdiene may also be employed, but it is more preferred to have the styrenebe present as a co-monomer. Copolymers of Isoprene and butadiene mayalso be used.

[0042] An important characteristics of the elastomer, particularly thetin-modified elastomers, is that a substantial portion, preferably atleast 40%, and more generally in the range of about 60 to about 85% ofthe tin (Sn) bonds or silicon (Si) bonds are bonded to the diene unitsof the styrene/diene copolymer, which may be referred herein astin-dienyl or silicon-dienyl bond, for example butadienyl bonds in caseof butadiene terminating with the tin (or silicon).

[0043] A modified copolymer elastomer may be prepared bycopolymerization of styrene with 1,3-butadiene and/or isoprene in anorganic solution with an alkyl lithium catalyst. A co-catalyst orcatalyst modifier may also be used. Such polymerization methods are wellknown to those skilled in this art. After formation of the copolymerelastomer, but while the catalyst is still active and, therefore, whilethe copolymer is still considered a living or live polymer that iscapable of further polymerization, the polymerization can be terminatedby reacting the live polymer with with a tin or silicon compound such astin tetrachloride. This taking into account that the valence of tin isfour, typically the modified copolymer is considered coupled or capped,with an accompanying molecular weight or viscosity jump or increase, andthe modified copolymer being in what is sometimes called as a starshaped, or star configured, coupled elastomer. Synthetic elastomers thatare made by emulsion polymerization techniques are are not amenable tosuch coupling techniques and are not intended to be employed in theblends of this invention.

[0044] A coupled styrene/isoprene/butadiene terpolymer may also be usedwhere the isoprene content is less than about 30% by weight or so of thesaid elastomer.

[0045] A tin coupled copolymer elastomer can also be obtained viacoupling with an organo tin compound such as for example alkyl tinchloride, dialkyl tin chloride, and trialkyl tin chloride, resulting invariations in the tin coupled polymer with the trialkyl tin monochlorideyielding simply a tin terminated copolymer.

[0046] Some examples of preparation of such modified elastomers isfurther given in following Journal Articles: “Solution-PolymerizedRubbers with Superior Breakdown Properties” Journal of Applied PolymerScience Vol. 14, PP 1421-1432 (1970), “Tin Coupled SBRs: Relationshipbetween Coupling Type and Properties, Paper No 78, Presented at 148^(th)Meeting of the Rubber Division, American Chemical Society, Cleveland,Ohio, Oct. 17-20, 1995, and “Newly Developed Solution SBRs for LowRolling Resistance Tire”, RCT 1990 V 63 #1, P 8-22, which areincorporated herein as a reference.

[0047] Some examples of modified or coupled solution elastomers such astin or silicon-coupled, with several variations are given in U.S. Pat.No. 6,090,880, U.S. Pat. No. 5,064,910, U.S. Pat. No. 4,553,578, U.S.Pat. No. 4,444,236, U.S. Pat. No. 5,362,794, U.S. Pat. No. 5,677,399,U.S. Pat. No. 5,786,441, U.S. Pat. No. 6,008,295, U.S. Pat. No.6,252,007, and U.S. Pat. No. 6,228,908, which are incorporated herein asa reference, as they may also be used in blends as disclosed in thisinvention.

[0048] The diene elastomers that are polymerized by solution techniquesthat may or may not be coupled with silicon or tin have severaladvantages due to the ability to tailor the elastomers with specificglass transition temperatures, styrene content, % butadienemicrostructure (1,2-butadiene or vinyl), and/ or changing the level ofbranching. It is generally preferred to have the modified dieneelastomer to have styrene content in the range of 5 to 45%, moregenerally in the 10 to 40% range, and most preferably in the 12 to 37%by weight of the said elastomer. It is known that the glass transitiontemperature of the said rubber may increase on increasing the styrenecontent. For applications that require low temperature impact propertiessuch as automotive fascia or side impact panels, it is generallypreferred to use the elastomer that has a glass transition temperatureno greater than −25° C., more preferred no more greater −40° C., mostpreferred no greater than −45° C.

[0049] U.S. Pat. No. 4,250,273 describes several diene monomers that maybe used to make solution polymers, which may be suitable to make thecoupled elastomers used in this invention, and is incorporated herein asa reference.

[0050] The diene based rubbers that are additionally useful for makingthe blend compositions are highly branched and may or may not beobtained via tin or silicon coupling. These diene elastomers arecharacterized in a dynamic mechanical thermal analyzer such as a RPAinstrument (Rubber Process Analyzer) by conducting a frequency sweep atan isothermal temperature of 100° C. The dynamic storage (G′) and lossmodulii (G″) and their ratio (G″/G′) or tangent delta are measured. Thefrequency in (radians/s) at which there is a crossover in the values ofG′ or G″ is measured i.e. the frequency at which the G′ and G″ valuesare equal, is measured. The frequency at which there is a crossover inthe values of G′ and G″ is much lower for the highly branched dieneelastomers than their rather unbranched or more linear analogs. Thesynthesis and RPA characterization of such uncoupled elastomers isdescribed in details in the publication “Synthesis and RheologicalCharacterization of Branched versus Linear Solution Styrene-butadieneRubber”, by Michael L. Kems, and Steven K. Henning, Paper No 52,Presented at the meeting of the Rubber Division, American ChemicalSociety, Rhode Island, Apr. 24-27, 2001, which is incorporated herein asa reference. The branched elastomers are believed to provide improvedcold flow resistance, more particularly for the crumb rubber form, andmay also provide improved processing in extrusion applications byremaining largely branched in the blend composition, more so in the TPEand TPV applications.

[0051] For the applications where the low temperature impact is not thatcritical, it may be acceptable to use the elastomer with a slightlyhigher glass transition temperature. These applications may be where thesoft touch or soft feel is desired from the said blend, which can beachieved by using an elastomer with the glass transition temperaturethat is generally less than 5° C., more generally less than 0° C., andmost generally less than −10° C. The modified elastomer may have the1,2-butadiene microstructure or the vinyl content varied from about 5%to about 95%, more generally from about 6% to about 65%, and mostgenerally from about 6% to about 58%. This flexibility in variation ofthe vinyl content is possible with the solution elastomers. The glasstransition of the elastomer may also increase with increasing vinylcontent. Therefore, applications requiring better low temperature impactproperties, a lower vinyl content is desirable. For applications wheresoft touch and soft feel is desired, higher vinyl content may bepreferred. Also, the resistance to ultraviolet (UV) radiation, ozone,and oxidation resistance may also be a function of the vinyl content,which may be achieved by a proper selection of the vinyl content.

[0052] For the use of the blend in injection molding applications, adiene based elastomer with a lower viscosity is preferred. It iscritical for the starting branched elastomer to be characterized by alow crossover frequency for improved cold-flow resistance and whereinthe branching is achieved in the elastomer by tin-coupling, it isdesired for the branched or star shaped architechture present in thesaid elastomer to break in the process of making or molding the blend.Certain compounding agents that facilitate the breaking of thetin-carbon bond in the elastomer may be employed, such as stearic acid,benzoic acid or rosin acid.

[0053] The Mooney viscosity (ML 1+4@100° C. ) of the said solutionrubber may be generally in the range of 10 to about 135, more preferablyfrom 25 to about 100, and most preferably from about 30 to about 80 orso. For making the TPO compositions, the polyolefin and the said rubberare mixed or kneaded around or above the melt point temperatures of thepolyolefin. For most polypropylenes, this temperature may be above 130°C., most generally above 145° C., and most preferably above 150° C.Typical polymer mixing or kneading equipment that is capable ofrendering heat and kneading may be employed. These include mills,kneaders, extruders (both single screw and twin-screw), Banbury mixers,calenders, and the like. The sequence of mixing and method may depend onthe final composition. A combination of Banbury batch mixers andcontinuous mixers may also be employed, such as a Banbury mixer followedby a mill mixer followed by an extruder. The extruder can be a single ortwin screw extruder. If a TPE or TPV composition is being obtained,typical batch mixers such as Banbury mixers may be employed to mix therubber and the thermoplastic till a homogeneous mixture is obtained. Forsuch TPE or TPV compositions, a continuous mixer such as a twin-screwextruder may also be used. Such TPE & TPV compositions may have a higherrubber loading when compared to the TPO compositions. Generallyspeaking, for the TPE and TPV compositions, the weight ratio of the saidrubber to the thermoplastic may be from about 90:10 to about 50:50, morepreferably from about 80:20 to about 60:40, and most preferably fromabout 75:25 to about 65:35 or so. For the TPO applications, the weightratio of the said rubber to the thermoplastic may be from about 49:51 toabout 10:90, more preferably from 35:65 to about 15:85. The ratios maybe changed by changing the viscosity ratios of the rubber and thethermoplastic. There is considerable art in the literature for changingthe phase continuity by changing the viscosity ratios of theconstituents and a person skilled in this art may vary the phasecontinuity by changing the viscosity ratios of the elastomer and thethermoplastic olefinic resin.

[0054] The blend compositions may contain processing oils, plasticizers,processing aids. Rubber processing oils have a certain ASTM designationsand may fall under paraffinic, napthenic or aromatic process oils andsuitable oils may be employed. The ordinarily skilled rubber chemistwill decide on the type of oil that may be used. The parts of oil usedmay be generally from about 0 to about 130 parts, more preferably about0 parts to about 100 parts, and most preferably about 0 parts to about50 parts, per 100 parts of the rubber or elastomer. Higher amounts ofoil may tend to improve the processing at the expense of some physicalproperties.

[0055] It is known that the high diene based rubbers have lowerresistance to UV, ozone, and oxidation, compared to the low-diene orrubbers with no olefinic unsaturation. It is also known that tires,which are primarily made from the high diene rubbers and often, containcarbon black along with anti-ozone and antioxidants , have a high degreeof reliability and durability in dynamic conditions of UV, ozone, andoxygen. Due to the unsaturation present in the elastomer, it is desiredto have a layer (coated, coextruded or laminated) of weather resistantfilm adhered to the blend formed with the diene elastomer andthermoplastic polyolefin.

[0056] For the TPO, TPV, and TPE applications, it is preferred that whenthe application accepts a black color, the rubber phase may preferablycontain the carbon black for the UV absorption characteristics.Representative examples of carbon blacks include ASTM N110, N121, N220,N231, N234, N242, N293, N299, S315, N326, N330, M332, N339, N343, N347,N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762,N765, N774, N787, N907, N908, N990 and N991. These carbon blacks haveiodine absorptions ranging from 9 to 145 g/kg and DBP No. ranging from34 to 150 cm3/100 g. It is more preferred that the particle size of thecarbon black is small.

[0057] The thermoplastic blends may also contain antiozonants andoxidants that are known to a rubber chemist of ordinary skill. Theantiozonants may be physical protectants such as waxy materials thatcome to the surface and protect the part from oxygen or ozone or theymay chemical protectors. The chemical protectors may be selected fromthe class of styrenated phenols, butylated octylated phenol, butylateddi(dimethylbenzyl) phenol , p-phenylenediamines, butylated reactionproducts of p-cresol and Dicyclopentadiene (DCPD, polyphenolicanitioxidants, hydroquinone derivatives, quinoline, diphenyleneantioxidants and thioester antioxidants and the like and their blends.Some representative trade names of such products are Wingstay® Santioxidant, Polystay® 100 antioxidant, Polystay® 100 AZ antioxidant,Polystay® 200 antioxidant, Wingstay® L antioxidant, Wingstay® LHLSantioxidant, Wingstay® K antioxidant, Wingstay® 29 antioxidant,Wingstay® SN-1 antioxidant, and Irganox® antioxidants. In someapplications, the antioxidants and antiozonants used will preferably benon-staining and non-migratory.

[0058] For applications that require non-black pigmentation orcompositions where the natural color may be desired, carbon black maynot be used and above mentioned antioxidants and antiozonant may be usedinstead. It is important that the said elastomer contains a significantportion of the antioxidant and antiozonant and/or carbon black (wheneverused) in the said blends.

[0059] For providing additional stability against UV radiation, hinderedamine light stabilizers (HALS) and UV absorbers may be also used. Askilled person is aware of such stabilizers. For example, Tinuvintm™ R123, 144, 622, 765, 770 and 780, and Chemisorb™ T-944 and the like maybe employed. These kinds of UV stabilizers are available from CibaSpeciality Chemicals and Cytex Industries. U.S. Pat. No. 6,051,681teaches the use of a HALS compound and a Lewis acid for achievingsuperior surface quality, which is incorporated herein as a reference.

[0060] For some compositions, additional mixing process may be employedto pre-disperse these anti-oxidants, antiozonants, carbon black, and UVabsorbers and light stabilizers in the said elastomer in a masterbatchform and then add them in the elastomer and plastic blending stage.

[0061] When the rubber phase is fully or partially cured in the TPO, andTPV compositions, curatives of the known art may be employed. The curingmay be accomplished by dynamic vulcanization, wherein the rubber phaseis generally crosslinked simultaneously as it is being mixed with thethermoplastic resin. The curatives may be selected from sulfur based,peroxide based, or phenolic based curatives. U.S. Pat. No. 3,758,643,U.S. Pat. No. 3,806,558, U.S. Pat. No. 5,051,478,U.S. Pat. No.4,104,210, U.S. Pat. No. 4,130,535, U.S. Pat. No. 4,202,801, U.S. Pat.No. 4,271,049, U.S. Pat. No. 4,340,684, U.S. Pat. No. 4,250,2734,927,882, U.S. Pat. No. 4,311,628 and U.S. Pat. No. 5,248,729 teach thetype of curing or crosslinking agents and methods which are incorporatedherein as a reference.

[0062] When sulfur based curing agents are employed, accelerators andcure activators may be used. Accelerators are used to control the timeand/or temperature required for dynamic vulcanization and to improve theproperties of the TPO or TPV. In one embodiment, a single acceleratorsystem may be used, i.e., primary accelerator. The primaryaccelerator(s) may be used in total amounts ranging from about 0.5 toabout 4, preferably about 0.8 to about 1.5, phr, where phr means perhundred parts of rubber. In another embodiment, combinations of aprimary and a secondary accelerator might be used with the secondaryaccelerator being used in smaller amounts, such as from about 0.05 toabout 3 phr, in order to activate and to improve the properties of theTPO or TPV. Combinations of these accelerators might be expected toproduce a synergistic effect on the final properties and are somewhatbetter than those produced by use of either accelerator alone. Inaddition, delayed action accelerators may be used which are not affectedby normal processing temperatures but produce a satisfactory cure atordinary vulcanization temperatures. Vulcanization retarders might alsobe used. Suitable types of accelerators that may be used in the presentinvention are amines, disulfides, guanidines, thioureas, thiazoles,thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, theprimary accelerator is a sulfenamide. If a second accelerator is used,the secondary accelerator is preferably a guanidine, dithiocarbamate orthiuram compound. Certain processing aids and cure activators such asstearic acid and ZnO may also be used. When peroxide based curing agentsare used, co-activators or coagents that are known to a rubber chemistof ordinary skill may be used in combination with the peroxides. Thesecoagents may include trimethylolpropane triacrylate (TMPTA),trimethylolpropane trimethacrylate (TMPTMA), triallyl cyanurate (TAC),Triallyl Isocyanurate (TAIC), and the like. The peroxide crosslinkersand the coagents that may be employed for partial or complete dynamicvulcanization can be selected from the journal publication, “PeroxideVulcanization of Elastomer”, Vol. 74, No 3, July-August 2001, which isincorporated here as a reference.

[0063] When the elastomer is at least partially crosslinked, especiallyin the TPVs, the degree of crosslinking may be measured by dissolutionof the blend in a solvent for specified duration, and using certaincalculations to compensate for the resin portion and then calculate %gel or unextractable rubber. The % gel would normally increase withincreasing crosslinking level. These techniques are well defined andestablished and are known to the persons that are skilled in this art.The % gel content in the thermoplastic blends, more so in the TPVs maybe anywhere in the range of about 5% to 100%.

[0064] The blends of the coupled-SBR and the polyolefin may showimproved processability. The improved processability may be due to thebreaking of tin-carbon due to shearing. These bonds may also be brokenrapidly by the addition of viscosity reducing agents such as stearicacid, benzoic acid, rosin acid, carbon black amine or acid containingmoieties and in the presence of an acceptable amount of shear and heat.Improved processability of the blend composition, more specifically theTPE or TPV compositions that have higher rubber content, may becharacterized by a lower viscosity of the blend or an improved surfaceappearance of the molded or extruded article. The The UV stabilizationand thermo-oxidative stabilization technology for the polyolefin resinsand their blends for TPOs, TPEs and TPVs are rather well developed. Tworecent articles and presentations describe these stabilizations indetail. These are: ‘Advances in UV Stabilization Systems for AutomotiveTPO’, Brent M. Sanders, Cytex Industries, Presented at the SPEAutomotive TPO Global Conference 2000, Hyatt Regency—Dearborn, Mich.,Oct. 2-4 2000, and ‘Stabilizer Selection Guidelines for Automotive TPOApplications’, James H. Botkin and Peter Solera, Ciba SpecialityChemicals Corporation, SPE Automotive TPO Global Conference 2001, HyattRegency—Dearborn, Mich., Oct. 1-3, 2001, which are incorporated hereinby reference. These stabilization systems may be essential for achievingthe UV and heat aging requirements that the TPOs have to meet,especially for the automotive applications.

[0065] The thermoplastic compositions may also contain reinforcingfillers such as talc, calcium carbonate (CaCO₃), glass fibers,expandable 2:1 layered silicates such as Smectite, Hectorite, mica andthe like, carbon black, silica, alumina for providing appropriate levelof reinforcement, wollastonite and graphite. Silane coupling agents mayalso be employed for better filler bonding. Talc is more preferred dueto its attractive cost and performance. Modified carbon blacks such asCRX 2000 series, CRX 4000 series of Cabot Corporation, modified starch,modified silica (pre-treated, doped) may also be used.

[0066] The thermoplastic compositions of this invention may be processedby conventional molding techniques such as injection molding, extrusion,thermoforming, slush molding, over molding, insert molding, blow moldingand the like. It is known to an ordinary person skilled in the art ofrheology to select the viscosity of the composition according to theappropriate process. For example, a low melt flow rate blend may berequired for extruding application and a high melt flow rate blend maybe required for an injection molding application for molding largeparts.

[0067] The thermoplastic compositions of the said invention may haveseveral useful applications and some of those include automotive,household goods, industrial appliances, recreation andcomputer/electronics equipment. In automotive area, exterior fascia orbumpers and side impact panels may be some examples. The fascias may bemolded in color or painted or may have a weather resistant film coatedon the surface. The automotive interior applications may also be severaland some of them can be door handles, knobs, instrument panels, roofimpact structures, applications replacing PVC etc. The automotiveinterior applications may also include components of vehicle thatrequire soft feel or soft touch. Also, impact resistant structural doorpanels may be made from these thermoplastic blends.

[0068] The thermoplastic compositions of this invention are ofparticular value for utilization in manufacturing flower stem holdercaps. Flower stem holder caps that are made with the thermoplasticcompositions of this invention offer the physical properties anddurability that are required in this application. For instance, suchflower holder caps are capable of firmly holding a flower arrangement inplace, capable of keeping water from spilling from a vessel such as avial or vase that holds the flower, and have the durability, includingcrack resistance, that is required for the flower holder cap to provideits required service life.

[0069] The flower holder caps of this invention can be made by moldingthe thermoplastic composition into the cap shape that is desired. Such adesign for a single flower is depicted in FIGS. 2, 3, 4 and 5. Thisflower holder cap design includes a hole 22 through which a flower stemcan be inserted and optionally vents 24 that provide for expansion andcontraction. The flower holder cap design shown in FIG. 3 includes ribs26 that help to prevent the spillage of water from vessels used totransport and/or display the flower. FIG. 4 illustrates a single flower42 being held in place in a flower transportation vessel 46 with aflower holder cap 20. The flower holder cap 20 firmly holds the stem 44of the flower 42 in place while preventing water within thetransportation vessel from spilling during transportation. This is aparticularly useful in cases where a single flower, such as a rose, ispurchased from a flower vendor and it is desired to keep the cut flowerstem in water during transportation and storage until the time of use.The flower holder cap depicted in FIG. 5 is equipped with a removal tab40 to facilitate the removal of the cap after usage.

[0070] A flower holder cap for holding an arrangement of multipleflowers in place is shown in FIGS. 6, 7, 8, and 9. This flower holdercap design includes holes 32 through which a flower stem can be insertedand optionally vents 34 that provide for expansion and contraction. Theflower holder cap design shown in FIGS. 7 and 8 includes ribs 36 thathelp to prevent the spillage of water from vessels used to transportand/or display the flower. FIG. 9 illustrates an arrangement of multipleflowers 42 being held in place in a vase with a flower holder cap 30 inthe neck of the vase. The flower holder cap 30 firmly holds the stems 44of the flowers 42 in place while preventing water within the vase 48from spilling and reducing the level of water lost through evaporation.The flower holder cap depicted in FIG. 8 is equipped with a removal tab40 to facilitate the removal of the cap after usage.

[0071] U.S. Pat. No. 5,962,573, U.S. Pat. No. 6,166,132, and U.S. Pat.No. 6,166,139 discloses compositions and methods for making directlypaintable TPO applications, and are incorporated herein as a reference.

[0072] This invention is illustrated by the following examples that aremerely for the purpose of illustration and are not to be regarded aslimiting the scope of the invention or the manner in which it can bepracticed. Unless specifically indicated otherwise, parts andpercentages are given by weight.

EXAMPLES

[0073] Solflex 3310 Sn (Solflex 3310 coupled with tin) SBR from TheGoodyear Tire & Rubber Company was used to make blends withpolypropylene resin. Solflex 3310 SBR is styrene-butadiene rubber (SBR)made by solution polymerization having a bound styrene content of about33% and a vinyl-microstructure content of about 10%. For comparisonpurposes, Solflex 3310 SBR (no coupling) of The Goodyear Tire & RubberCompany was used. The microstructure are listed in Table 1. TABLE 1Composition & Microstructure in Weight % Cis- Trans- Rubber Styrene1,2-butadiene 1,4 butadiene 1,4-butadiene Solflex 3310 34.1 7.9 21.836.2 Sn SBR Solflex 3310 32.5 7 23.9 36.6 SBR

[0074] The glass transitions temperatures (midpoint) of Solflex 3310 SnSBR and Solflex 3310 SBR were measured in a differential scanningcalorimetry (DSC. ) at a 10° C. heating rate and were −55° C. and −50°C. respectively. Elastomers with low glass transition temperatures willprovide low temperature impact properties. Frequency sweeps were carriedout at 100° C. for the Solflex 3310 Sn SBR and the Solflex 3310 SBR at0.63 degree strain in the frequency range 0.21 radians/s to 209.44radians/s. The G′ and G″ values converged and crossed over at afrequency of 5 radians/s for the tin coupled Solflex 3310 SBR. The G′and G″ values were converging and the crossover point was not measurablein the frequency range employed with the lowest frequency being about0.21 radians/sec. This indicates that the crossover frequency of Solflex3310 tin (Sn) was lower than 0.21 radians. The bale form of rubbers wasconverted to a crumb or particulate form by grinding the rubber in thepresence of talc partitioning agent. In the experiments, othernanoparticulates, such as powdered PE, calcium carbonate and powderedsilica, were used as the partitioning agent with good results. The crumbform may also be obtained towards the finishing operation of thesolution polymerization process for the elastomer before compacting itto the bale form.

[0075] The final composition of the crumb rubber was 95% rubber and 5%talc on a weight basis. About 25 lbs. (11.33981 kg) of talc-partitionedand ground or crumb Solflex 3310 Sn SBR and Solflex 3310 SBR wereseparately packaged in a plastic bag and stored in individual cardboardboxes for about 7 days, without any additional weight on the bags. Thebags were opened for conducting further mixing experiments in thetwin-screw extruder. The Solflex 3310 Sn SBR crumb rubber was stillusable for feeding in the extruder as a crumb rubber, whereas theSolflex 3310 SBR (uncoupled) rubber had massed together to form largelumps that were not breakable without re-grinding. This demonstratesless cold flow for a crumb form of tin-coupled diene elastomer thatcontains a partitioning agent, when compared with its uncoupled Solflex3310 SBR analog.

[0076] Blends of the crumb form of Solflex 3310 Sn SBR or Solflex 3310SBR were made with a high impact copolymer polypropylene (BPAmoco-3451). The blends were made in a 43 mm twin-screw-extruder ofBerstroff, with co-rotating and intermeshing screw profile with an L/Dof 32 as generally depicted in FIG. 1. The extruder had side-feedingcapability at Barrel 3 located approximately 50 percent downstream ofthe main feed zone. The extruder has six heated barrels and a heated diesection and the temperature (° C. ) that was used in the barrels (1-6) &die section are 185, 185, 185, 185, 177, 177, and 177 (die). The RPMthat was used for mixing was set to 135. A total feed rate of about 75lbs/hr (34.01943 kg/hr) was used for the study. In the examples shownthe polypropylene and talc-partitioned rubber are fed in the feedhopper.

[0077] Due to the shearing action between the extruder elements and thepolypropylene resin, the resin was melted and mixed with the rubber. Theblends were extruded and pelletized. Blend compositions that are high inpolypropylene content and can be used in the TPO applications are listedin Table 2. TABLE 2 Blend Composition in Weight % Example 1 Example 2Solflex 3310 SBR — 28.5 Solflex 3310 Sn SBR 28.5 — Talc 1.5 1.5Polypropylene 70 70 (3451 Copolymer) Rubber Feed FH FH Location*Residence Time(s)** 70 70

[0078] The blends were injection molded by injection molding techniqueby melting the blend about the melt point of polypropylene. It ispossible to form some of the articles of manufacture such as extrudablesheets or profiles at the end of the mixing step by providing a die.Molded samples were prepared from the injection molded blends and weretested for physical properties with following results as given in Table3. TABLE 3 Physical Properties Example 2 Example 1 (Compar.) TensileStrength (psi)  1671  1849 Elongation @ Break  408  404 (%) Notched IzodImpact 12.44 (NB) 10.22 (NB) (ft-lb/in)*** Flexural Modulus 62699 67053(psi)

[0079] Thermoplastic blends of Example 2 that were prepared with Solflex3310 Sn SBR and were fed in the feed hopper for additional mixingresulted in compositions with very high impact strength and a goodbalance of physical properties. The crumb and partitioned form ofSolflex 3310 Sn SBR that was used to make the blends has higherresistance to agglomeration and has an advantage for supplying therubber in a crumb form for feeding into continuous mixers such astwin-screw extruders.

[0080] In the next set of trials, thermoplastic compositions wereprepared that had higher rubber contents. The blends were prepared in an18-mm Leistritz, co-rotating twin-screw extruder. All ingredients werefed in the main feed hopper and melt mixed at a temperature of aboveabout 160° C. The compositions are given in Table 3. The Solflex 3310 SnSBR and Solflex 3310 SBR contained 5% by weight of talc partitioningagent. TABLE 3 Blend Composition in Weight % Com- parative ComparativeExample 3 Example 4 Example 5 Example 6 Solflex 3310 Sn SBR 66.16 64.93— — (with talc) Solflex 3310 SBR — — 66.16 64.93 (with talc)Polypropylene 33.84 33.22 33.84 33.22 (Atofina 7823 M Random CopolymerMFI 30 g/10 minutes 230 C/2.16 Kg) Stearic Acid — 1.85 — 1.85 Total 100100 100 100

[0081] The physical properties of the blends are given in Table 4. TABLE4 Blend Physical Properties & Viscosity Example 5 Example 6 Example 3Example 4 (Compar.) (Compar.) Apparent Viscosity 72.8 59.2 70.8 67.1(200° C.) in (Pa · s) @ 3648.4 (l/s) Apparent Viscosity 145.9 107.4144.7 137.5 (200° C.) in (Pa · s) @ 1459.4 (l/s) Tensile Stress @ Yield6.6 7.3 6.7 6.4 (MPa) Elongation @ Break % 315 461 300 159 Stress @ 100%6.1 6.2 6.2 6.0 elongation

[0082] When comparing Example 4 that contains the highly branchedelastomer and the stearic acid for breaking the the tin-carbon bond,Example 4 had the lowest viscosity across the measured shear rate range,indicating better flowability and processability with good overallphysical properties. Lower viscosity of the blend is believed to beattributed to the breaking of the tin-carbon bonds of the branchedelastomer when melt blended with the polypropylene.

[0083] The compositions may be further modified to improve the scratchresistance of the high elastomer compositions by dynamically vulcanizingthe elastomer with the help of crosslinking agents. The examples aretypical and several variations are possible without deviating from thescope of the invention.

[0084] While certain representative embodiments and details have beenshown for the purpose of illustrating the subject invention, it will beapparent to those skilled in this art that various changes andmodifications can be made therein without departing from the scope ofthe subject invention.

What is claimed is:
 1. A thermoplastic composition which is comprised ofa blend of a thermoplastic polyolefin resin and a modified elastomer,wherein said thermoplastic polyolefin resin selected at least from thegroup of polyethylene, isotactic polypropylene, syndiotacticpolypropylene, polypropylene impact copolymers containing about 1-7% byweight of ethylene, butene, hexene, or octene, polyolefin copolymers,polybutene, reactor grade modified polypropylene, oxypolyolefin,metallocene polypropylene, wherein said modified elastomer is comprisedof a conjugated diene selected from 1,3-butadiene and isoprene, whereinsaid modified elastomer is highly branched, wherein said modifiedelastomer is characterized by having a G′ and G″ frequency crossover ofno more than 4 radians/s at 100° C., wherein the thermoplasticpolyolefin is present in an amount which is within the range of about 5parts by weight to about 95 parts by weight, and wherein the modifiedelastomer is present in an amount which is within the range of about 5parts by weight to about 95 parts by weight, based upon the total weightof the thermoplastic composition.
 2. A thermoplastic composition asspecified in claim 1 wherein the modified elastomer is at leastpartially crosslinked in the thermoplastic composition.
 3. Athermoplastic composition as specified in claim 2 wherein said modifiedelastomer is further comprised of a vinyl aromatic monomer selected fromthe group consisting of styrene and alpha-methylstyrene.
 4. Athermoplastic composition as specified in claim 1 wherein thethermoplastic polyolefin is present in an amount which is within therange of about 20 parts by weight to about 80 parts by weight, andwherein the modified elastomer is present in an amount which is withinthe range of about 20 parts by weight to about 80 parts by weight, basedupon the total weight of the thermoplastic composition.
 5. Athermoplastic composition as specified in claim 2 wherein the modifiedelastomer is coupled with a member selected from the group consisting oftin and silicon.
 6. A thermoplastic composition as specified in claim 1wherein the thermoplastic resin used has a melt flow rate of at leastgreater than 0.5 g/10 minutes as measured by ASTM D 1238 at 230° C./2.16kg load.
 7. A thermoplastic composition as specified in claim 2 whereinthe said blend has a melt flow rate of at least greater than 0.5 g/10minutes per ASTM D 1238 at 230° C./2.16 kg load.
 8. A thermoplasticcomposition as specified in claim 1 wherein the modified elastomer has aMooney ML 1+4 viscosity at 100° C. which is within the range of about 10to about
 135. 9. A thermoplastic composition as specified in claim 1wherein where the modified elastomer used has a Mooney ML 1+4 viscosityat 100° C. which is within the range of about 30 to about
 80. 10. Athermoplastic composition as specified in claim 1 wherein the melt pointof the thermoplastic polyolefin resin is at least 75° C. as measured bydifferential scanning calorimeter at a heating rate of 10° C./minute.11. A thermoplastic composition as specified in claim 1 wherein theparticle size of a major portion of the modified elastomer in the blendis smaller than 50 microns.
 12. A thermoplastic composition as specifiedin claim 1 wherein the particle size of a major portion of the modifiedelastomer in the blend is smaller than 10 microns.
 13. A thermoplasticcomposition as specified in claim 1 wherein the modified elastomer has a1,2-vinyl butadiene microstructure content which is within the range ofabout 0 to about 90% by weight.
 14. A thermoplastic composition asspecified in claim 1 wherein the modified elastomer has a 1,2-vinylbutadiene microstructure content which is within the range of about 20to about 60% by weight.
 15. A thermoplastic composition as specified inclaim 1 wherein the modified elastomer has a glass transitiontemperature in the range of −80° C. to about 10° C. as measured bydifferential scanning calorimeter at a heating rate of 10° C./minute.16. A thermoplastic composition as specified in claim 3 wherein thevinyl aromatic monomer is present in the modified elastomer at a levelwhich is within the range of about 5 weight percent to about 50 weightpercent.
 17. A thermoplastic composition as specified in claim 1 whereinsaid thermoplastic composition is further comprised of a member selectedfrom the group consisting of processing oil, processing aids, andplasticizers in an amount which is within the range of about 5 parts byweight to about 50 parts by weight, based upon the weight of themodified elastomer in the thermoplastic composition.
 18. A thermoplasticcomposition as specified in claim 1 wherein an antidegradant is presentin the modified elastomer.
 19. A thermoplastic composition as specifiedin claim 17 wherein the antidegradant is an antioxidant or anantiozonant selected at least from the group of styrenated phenols,butylated octylated phenol, butylated di(dimethylbenzyl) phenol ,p-phenylenediamines, butylated reaction products of p-cresol anddicyclopentadiene, polyphenolic anitioxidants, hydroquinone derivatives,quinoline, phosphites, diphenylene antioxidants, and thioesters.
 20. Athermoplastic composition as specified in claim 1 wherein saidthermoplastic composition is further comprised of an ultra-violet lightprotector selected from the group of carbon black and hindered aminelight stabilizers.
 21. A thermoplastic composition as specified in claim1 wherein said thermoplastic composition is further comprised of areinforcing filler selected from the group consisting of silica, carbonblack, kaolin clay, talc, calcium carbonate, glass fibers, alumina,wollastonite, graphite and expandable 2:1 layered silicates.
 22. Aprocess for preparing a thermoplastic composition which comprised (1)mixing a thermoplastic polyolefin resin and a modified elastomer at atemperature about or above the melting point of the thermoplastic resinin a mixing devise, (2) discharging the mixed blend from the mixingdevise, and (3) forming the mixed blend into a pellet, sheet, or articleof manufacture, wherein said thermoplastic polyolefin resin selected atleast from the group of polyethylene, isotactic polypropylene,syndiotactic polypropylene, polypropylene impact copolymers containingabout 1-7% by weight of ethylene , butene, hexene, or octene, polyolefincopolymers, , polybutene, reactor grade modified polypropylene,metallocene polypropylene, oxypolypropylene, wherein said modifiedelastomer is comprised of a conjugated diene selected from 1,3-butadieneand isoprene, wherein said modified elastomer is highly branched,wherein said modified elastomer is characterized by having a G′ and G″frequency crossover of no more than 4 radians/s at 100° C., wherein thethermoplastic polyolefin is present in an amount which is within therange of about 5 parts by weight to about 95 parts by weight, andwherein the modified elastomer is present in an amount which is withinthe range of about 5 parts by weight to about 95 parts by weight, basedupon the total weight of the thermoplastic composition.
 23. A process asspecified in claim 21 wherein the mixer is a batch mixer.
 24. A processas specified in claim 21 wherein the mixer is a continuous mixer.
 25. Aprocess as specified in claim 21 wherein the thermoplastic compositionfurther comprises a member selected from the group consisting of acrosslinking agent, an accelerator, a cure activator that is selected atleast from the group consisting of peroxides, sulfur, sulfur donors,zinc oxide, stearic acid, a phenolic resin, amines, disulfides,guanidines, thioureas, thiazoles, thiurams, sulfenamides,dithiocarbamates and xanthates.
 26. A process as specified in claim 21wherein the thermoplastic composition is formed into an article ofmanufacture selected from the group consisting of automotive interiorpanels, automotive exterior body panels, automotive instrument panels,soft-touch parts, household appliances, household goods, toys, razorholders, razor handles, stapler handles, pen grips, and computer keyboards.
 27. A process as specified in claim 21 wherein the thermoplasticpolyolefin resin and a modified elastomer are mixed by the applicationof shear.
 28. A process as specified in claim 26 wherein the modifiedelastomer and the thermoplastic resin are intimately mixed.
 29. Athermoplastic composition as specified in claim 2 wherein saidthermoplastic composition is further comprised of a viscosity reducingagent.
 30. A thermoplastic composition as specified in claim 2 whereinsaid thermoplastic composition is further comprised of an acid selectedfrom the group consisting of stearic acid, benzoic acid and rosin acid.31. A thermoplastic composition which is comprised of a blend of athermoplastic polyolefin resin and a modified elastomer, wherein saidthermoplastic polyolefin resin selected at least from the group ofpolyethylene, isotactic polypropylene, syndiotactic polypropylene,polypropylene impact copolymers containing about 1-7% by weight ofethylene, butene, hexene, or octene, polyolefin copolymers, polybutene,reactor grade modified polypropylene, oxypolyolefin, metallocenepolypropylene, wherein said modified elastomer is comprised of aconjugated diene selected from 1,3-butadiene and isoprene, wherein themodified elastomer is coupled with tin or silica, wherein said modifiedelastomer is highly branched, wherein the thermoplastic polyolefin ispresent in an amount which is within the range of about 5 parts byweight to about 95 parts by weight, and wherein the modified elastomeris present in an amount which is within the range of about 5 parts byweight to about 95 parts by weight, based upon the total weight of thethermoplastic composition.
 32. A process for preparing a thermoplasticcomposition which comprised (1) mixing a thermoplastic polyolefin resinand a modified elastomer at a temperature about or above the meltingpoint of the thermoplastic resin in a mixing devise, (2) discharging themixed blend from the mixing devise, and (3) forming the mixed blend intoa pellet, sheet, or article of manufacture, wherein said thermoplasticpolyolefin resin selected at least from the group of polyethylene,isotactic polypropylene, syndiotactic polypropylene, polypropyleneimpact copolymers containing about 1-7% by weight of ethylene, butene,hexene, or octene, polyolefin copolymers,, polybutene, reactor grademodified polypropylene, metallocene polypropylene, oxypolypropylene,wherein said modified elastomer is comprised of a conjugated dieneselected from 1,3-butadiene and isoprene, wherein the modified elastomeris coupled with tin or silica, wherein said modified elastomer is highlybranched, wherein the thermoplastic polyolefin is present in an amountwhich is within the range of about 5 parts by weight to about 95 partsby weight, and wherein the modified elastomer is present in an amountwhich is within the range of about 5 parts by weight to about 95 partsby weight, based upon the total weight of the thermoplastic composition.33. A thermoplastic composition as specified in claim 1 wherein thethermoplastic polyolefin resin is ethylene vinyl acetate.
 34. A flowerholder cap which is comprised of the thermoplastic composition specifiedin claim 1 wherein the flower holder cap is of a cap shaped design withat least one hole therein and wherein the hold is adapted for insertingthe stem of a flower therein.